Stain resistance, water repellency and resistance to microbial growth are important in many uses of textile materials. In restaurants, for example, table cloths and seating upholstery often lack stain resistance and are subject to rapid water penetration. These properties necessitate frequent cleaning and/or replacement of such items. Although one generally views microbial growth as associated with fibers of biologic origin such as cotton, wool, linen and silk, in the field of marine use, the high relative humidity renders even synthetic polymer textiles such as polyesters and polyamides subject to microbial growth, which is also true of many other outdoor uses.
Textile fabrics may be made water resistant by various processes. For example, textile fabrics may first be scoured with a soap solution and then treated with a composition which may include zinc and calcium stearates as well as sodium soaps. The long chain carboxylic acid hydrophobic compounds provide a limited amount of water repellency. It is also possible to render fabrics liquid resistant by treating the fabric with commercially available silicone, for example poly(dimethylsiloxane).
To overcome problems associated with water absorption and stain resistancy, resort has been made to synthetic leathers and polyvinylchloride (vinyl) coated fabrics. However, these fabrics do not have the hand or feel of cloth, and in general, are difficult and in many cases impossible to print economically. Moreover, although attempts have been made to render such materials water vapor permeable. these attempts have met with only very limited success, as evidenced by the failure of synthetic leather to displace real leather in high quality seating and footwear.
Although the treating and coating methods discussed previously may assist in rendering the fabric partially liquid and/or stain resistant, fabrics thusly treated or coated cannot be satisfactorily printed. The treated liquid resistant fabrics refuse to accept or become incompatible with the application of color dyes. The polymeric coated liquid resistant fabrics cannot be transfer printed because the heat required in the printing process generally causes the polymeric coating to melt or deform. Thus, if a fabric with a particular design or logo is required, the textile fabric must be printed first by traditional methods, following which it may be treated or polymer coated. However, the polymer coating generally obscures the design due to its thickness and opacity, even when non-pigmented vinyl, for example, is used.
Applications of fluorochemicals such as the well known SCOTCHGUARD.TM. and similar compounds also may confer a limited degree of both water repellency and stain resistance. However, for optimal water repellency, it has proven necessary to coat fabrics with thick polymeric coatings which completely destroy the hand and feel of the fabric. Examples include vinyl boat covers, where the fabric backing is rendered water resistant by application of considerable quantities of polyvinylchloride latex or the thermoforming of a polyvinyl film onto the fabric. The fabric no longer has the hand and feel of fabric, but is plastic-like. Application of polyurethane films in the melt has also been practiced, with similar results. However, unless aliphatic isocyanate-based polyurethanes are utilized, the coated fabric will rapidly weather.
In many industrial, institutional, and commercial applications, severe flame retardant properties are required. Upholstered furniture must often pass the stringent so-called Boston chair or U.K. Crib 5 tests. In these tests, a bag with a weighed quantity of dry newspaper or a crib of wood of specified weight is placed onto the chair and ignited. As the seating cushions, whether of the enclosed spring type with cotton or polyester cushioning, or of the more prevalent polyurethane foam cushioning, are themselves flammable, the cushions in general necessitate covering with a flame barrier of woven fiberglass or the like, then covering with printed upholstery fabric. Fiberglass flame barriers tend to make the cushioning less comfortable as well as creating the potential for penetration of irritating glass fibers into the occupant.
Improvements in flame barriers are disclosed in U.S. Pat. Nos. 4,921,756, 4,996,099, and 5,091,243. In these patents, flame barriers of corespun yarns employing glass or other non-flammable fibers in the core are overwrapped with staple or continuous intumescent polymeric synthetic fibers. However, these barriers, while increasing the comfort of the upholstered furniture, are not liquid or stain resistant, and must still be covered by an exterior printed fabric. Thus, additional manufacturing steps are necessary.
It would be desirable to provide a liquid resistant fabric that may be printed. It would be further desirable to provide a liquid and stain resistant, antimicrobial fabric that may be printed. It would be yet further desirable to provide a fabric that allows water vapor to pass through the fabric while prohibiting the passage of liquid. It would also be desirable to provide a method of producing a liquid and stain resistant, antimicrobial fabric that may be subsequently printed. It would further be desirable to provide a printed, liquid and stain resistant, antimicrobial fabric that retains its natural hand and texture, is easy to handle, and economical to produce. It would still yet further be desirable to provide a liquid resistant, stain resistant, printed fabric which has flammability properties similar to those of flame barrier fabrics.